Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Transcriptomic profiling of peripheral blood mononuclear cells from healthy individuals

ABSTRACT: Substantial effort is currently devoted to identifying cancer-associated alterations using genomics. Here, we show that standard blood collection procedures rapidly change the transcriptional and post-transcriptional landscapes of hematopoietic cells, resulting in biased activation of specific biological pathways, up-regulation of pseudogenes, antisense RNAs, and unannotated coding isoforms, and RNA surveillance inhibition. Affected genes include common mutational targets and thousands of other genes participating in processes such as chromatin modification, RNA splicing, T and B cell activation, and NF-κB signaling. The majority of published leukemic transcriptomes exhibit signals of this incubation-induced dysregulation, explaining up to 40% of differences in gene expression and alternative splicing between leukemias and reference normal transcriptomes. The effects of sample processing are particularly evident in pan-cancer analyses. We provide biomarkers that detect prolonged incubation of individual samples, and show that keeping blood on ice markedly reduces changes to the transcriptome. In addition to highlighting the potentially confounding effects of technical artifacts in cancer genomics data, our study emphasizes the need to survey the diversity of normal as well as neoplastic cells when characterizing tumors. This study is complemented by GSE61410: transcriptomic profiling of bone marrow cells from healthy individuals. Peripheral blood mononuclear cells (PBMCs) were isolated from four healthy individuals, following an ex vivo incubation of variable length at either room temperature or on ice. RNA transcriptomes were measured using the Illumina HiSeq.

ORGANISM(S): Homo sapiens

SUBMITTER: Heidi Dvinge

PROVIDER: E-GEOD-58335 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Similar Datasets

Project description:ABSTRACT: Exposure to abiotic stresses triggers global changes in the expression of thousands of eukaryotic genes at the transcriptional 70 and post-transcriptional levels. Small RNA (smRNA) pathways and splicing both function as crucial mechanisms regulating stress-responsive gene expression. However, examples of smRNAs regulating gene expression remain largely limited to effects on mRNA stability, translation, and epigenetic regulation. Also, our understanding of the networks controlling plant gene expression in response to environmental changes, and examples of these regulatory pathways intersecting, remains limited. Here, to investigate the role of smRNAs in stress responses we examined smRNA transcriptomes of Brachypodium distachyon plants subjected to various abiotic stresses. We found that exposure to different abiotic stresses specifically induced a group 75 of novel, endogenous small interfering RNAs (stress-induced, UTR-derived siRNAs, or sutr-siRNAs) that originate from the 3M-bM-^@M-2 UTRs of a subset of coding genes. Our bioinformatics analyses predicted that sutr-siRNAs have potential regulatory functions and that over 90% of sutr-siRNAs target intronic regions of many mRNAs in trans. Importantly, a subgroup of these sutr- siRNAs target the important intron regulatory regions, such as branch point sequences, that could affect splicing. Our study indicates that in Brachypodium, sutr-siRNAs may affect splicing by masking or changing accessibility of specific cis-elements 80 through base-pairing interactions to mediate gene expression in response to stresses. We hypothesize that this mode of regulation of gene expression may also serve as a general mechanism for regulation of gene expression in plants and potentially in other eukaryotes. Analysis of smRNA populations in Brachypodium plants challenged by abiotic stresses: To profile the populations of smRNAs in the model monocot Brachypodium distachyon and examine their regulation in response to abiotic stresses, we conducted high-throughput sequencing of small RNAs from plants exposed to four different abiotic stress conditions, cold, heat (air), heat (water immersion), and salt, in the wild type Brachypodium cultivar Bd21. For our experiments we used information from the literature to select two time-points for stress durations, short and long, which differed for each stress: cold (6 and 24 hours), heat-air (1 and 3 hours), heat-water (1 and 3 hours), and salt (48 hours). We generated small RNA libraries for Illumina sequencing (GAII) from the leaves of Brachypodium plants subjected to stresses and selected smRNAs between 15 and 40 nt in length, which we mapped to the Brachypodium genome.

Project description:Recent data from several organisms indicate that the transcribed portions of genomes are larger and more complex than expected, and many functional properties of transcripts are not based on coding sequences but on regulatory sequences in untranslated regions or non-coding RNAs. Alternative start and polyadenylation sites and regulation of intron splicing add additional dimensions to the rich transcriptional output. This transcriptional complexity has been sampled mainly using hybridization-based methods under one or a few conditions. We applied direct high-throughput sequencing of cDNAs, complemented with different expression data from high-density tiling arrays, to globally sample transcripts of the fission yeast Schizosaccharomyces pombe, independently from available gene annotations. We interrogated transcriptomes under multiple conditions, including exponential proliferation, meiotic differentiation and environmental stress, and in RNA processing mutants, to reveal the dynamic plasticity of the transcriptional landscape as a function of environmental, developmental, and genetic factors. High-throughput sequencing proved to be a powerful and quantitative method to deeply sample transcriptomes at unprecedented resolution. Unlike hybridization, sequencing showed little, if any, background noise and was sensitive enough to detect widespread transcription in >90% of the genome, including traces of RNAs that were not actively transcribed or rapidly degraded. The combined sequencing and strand-specific array data provided rich information on novel, mostly non-coding transcripts, untranslated regions and gene structures, thus refining the existing genome annotation. Sequence trans-reads spanning exon-exon or exon-intron junctions gave unique insight into a surprising variability in splicing efficiency across introns and genes. Splicing efficiency was largely coordinated with transcriptional efficiency, and hundreds of introns showed regulated splicing as a function of cellular proliferation or differentiation.

Dataset Information

Transcriptomic profiling of peripheral blood mononuclear cells from healthy individuals

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets